A redundant pair of routers operates in active-standby mode. Each of them being ready to take over the other router’s servicing function in case of a failure.
When a failure of the router servicing access to node 1 is detected, the standby router takes over using one of the following protocols:
Virtual router redundancy protocol (VRRP)
Hot-standby router protocol (HSRP)
Parent topic: Cluster Redundancy